It's theft pure and simple, both morally and legally, if you really understand the underlying theory as presented by HarryB, bob from maine, and others. And yes, it is also illegal to 'decode' the encrypted signal from DirecTV or Dish TV although 'viewing' the decoded signal will probably be the secondary infraction. But all this legal stuff takes away from primary presentation of the article.

I think it's great that a new student has discovered this phenomenon for himself, either independently or as an extension of his studies. At some point in time all EE's had this same idea until we were nudged by the more 'experienced ones' (professors, teachers, etc) to review the theory and conclude for ourselves if the EM field produced is 'waste' energy or if the parasitic device is really just another load, drawing more energy from the source than was supplied or intended. As for range, the electromagnetic field is a fundamental force that will always encroach on someone's property since it has infinite range.

Great idea for a new product, Chuck_IAG. If you were to design something to 'harvest' the free, unintended energy in a car crash (instead of delivering it to the occupants) you'd be a wealthy, wealthy man. I agree the power companies do not want to own the 'free space' energy arounf their power lines, for exactly the reasons you note. However... adding an apparatus to harvest power (for yourself) is exactly the same as if you climbed the pole and tied a wire to theirs. As others have elegently said... making an antenna draws MORE power than the free space would have... measureably more power... and that can be interpreted (as the courts have done) as theft. They lost (power), you gained it. If you made a device to drain a portion of the fuel from cars as they passed (that they were not otherwise leaking...) that too would be theft. They lost (fuel) you gained it. The free 'harvested' energy isn't yours to take, because it wasn't free in the first place.

I believe it is a mistake to say that the power you can draw from the grid's EM fields would otherwise be "wasted." The amount of EM energy that radiates out from the power lines is set by the impedance of the space they couple into. If you set up an antenna, you alter that impedance and so more energy flows into that space than would have otherwise. Hence, you've taken power from the source. You're not gathering power that would otherwise have been wasted in the surrounding space. That power is still being wasted in the surrounding space. The antenna has simply added a new load onto the source.

One small phone charger would not have a noticable impact on the grid, but if millions of people in a city were to try to capture energy that way, it certainly would.

ungarata, if you simply take the RF power reaching your property, then the satellite providers won't come after you. But ify ou decode their signals, they consider that theft of service and they will come after you. There have even been cases of groups that meet to discuss and share the technology of decoding being treated as criminal conspiracy organizations as the purpose for such discussions is assumed to be collaborating to steal service.

If you make a noticable dent in the power grid by harvesting from their EM fields, the power companies may well prosecute. If, however, you take that radiated energy from the power lines inside your house, you've been metered for it and so you have already paid.

I think sensor pro has some interesting points. Power companies have certainly distanced themselves from EM radiation coming from their equipment and spent a ton of money "proving" it doesn't cause or even influence medical problems of those living near high-power lines--that's what the business of the entirely non-objective Electric Power Research Institute is all about. OTOH, why the heck aren't they harvesting "waste" energy themselves? Many posts have addressed the science of this issue, and even some of the ethics, but few have said anything about social or economic implications.

@HarryB, you may have hit on the pertinent point in a wider discussion of rights. If someone hits your car at high speed with their own, they are "delivering" free energy to you. Should they be able to charge you for that? I think the ability to control the distribution of an energy or information source is critical to whether it might be considered "stolen" or "harvested" (or "imposed" for that matter). For a power company to attempt to claim ownership of the waste EM energy from power lines would subject them to even more lawsuits from parents who charge that living near a substation caused leukemia in their kids. I seriously doubt the companies would claim the energy back. They can't control the energy release. If your car leaked fuel on the street, and someone came along with a rag and sopped up the fuel with it, could you sue the person to recover the cost of your fuel?

I don't actually know the answer to that, but I tend to doubt that the matter is so clear-cut as to be able to call the energy "stolen".

On the other hand, a year ago I watched a Youtube video (since removed) with a schematic for a device that charges a small battery from radio waves. The idea was to charge a cell phone in an emergency- in a few hours the guy could turn on his phone (for a brief period). As others have said, nothing shockingly new here.

Most of the arguments in the posts have been argued before. As noted there is no free lunch. As much as I would like to disagree the only "free" energy is that which no one paid to generate initially (e.g. sunlight). Someone has even already argued that there will be a price paid for the waste heat generated as a result of capturing the additional sunlight. The one idea I have not seen commented on is that of Tesla. He wished to build a tower that could be used to transmit energy which could be harvested at a distant location. It was started and never completed. There are those today that hope to resurrect the project. I doubt that this would provide free power, but it might make delivering the power to a remote location easier if it could ever be achieved.

Guess what. You can hold up your cell phone and measure the amoount of energy being eaten by your phone at a specific frequency. Every antenna is designed to pull energy out of thin air at specific frequencies and provide it for amplification by a receiver. The amount of actual power you can pull out of the air is proportional to the amount of hardware and software you've installed to do it. Pulling enough power from the grid to power a toaster or other appliance may not be very be cost effective.

There are many cases where power companies tried o distance themselves from any ownership of he magneic byproduct not to be sued for medical problems of residents next to power lines. I have this feeling that ConEdison will not go after me is I park my car on the street and while having luch, my phone will charge.

On the other hand so much power is being wasted, and this is one little way that some can be used again and again.

Yes, I had a friend that owned a farm about 50 years ago with high-tension lines running on his lot line. He ran a wire looping several times around his acreage on his fence, simulating a very large transformer coil, and ran the two ends through a transformer and rectifier that charged a bank of batteries that ultimately powered his farmhouse. His coil put an extra load on the transmission system which was detectable as a load on the power grid. The power company somehow tracked him down, resulting in heavy fines and prosecution for theft. As mention in other replies, you don't have legal ownership or rights to everything in your "space".

A few weeks ago, Ford Motor Co. quietly announced that it was rolling out a new wrinkle to the powerful safety feature called stability control, adding even more lifesaving potential to a technology that has already been very successful.

It won't be too much longer and hardware design, as we used to know it, will be remembered alongside the slide rule and the Karnaugh map. You will need to move beyond those familiar bits and bytes into the new world of software centric design.

People who want to take advantage of solar energy in their homes no longer need to install a bolt-on solar-panel system atop their houses -- they can integrate solar-energy-harvesting shingles directing into an existing or new roof instead.

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